DescriptionBACKGROUND OF THE INVENTION
Internal combustion engines, such as those found in automobiles, trucks, and other vehicles, contain reciprocating pistons outfitted with expandable rings fitted into grooves cut into the exterior circumferences of the pistons. The rings aredesigned to expand and contract as the pistons and piston walls expand and contract due to heat generated by the engine in order to prevent the passage of oil into the firing chamber and to contain the combustion products of the engine within thecombustion chamber. Over periods of use, the ring grooves become contaminated with burned carbon and other foreign materials generated through the combustion cycle. Contamination of the grooves prevents efficient expansion and contraction of the ringsand diminishes the efficiency of the engine.
Typically after prolonged periods of use, internal combustion engines may be dismantled and the rings of the pistons replaced. If the accumulation of carbon and other foreign matter in the grooves is great enough to prevent proper functioning ofthe rings, the grooves are normally cleaned of the carbon and other foreign material. In the past this has been a very difficult and time consuming task. Mechanics have resorted to sharp instruments, such as chisels, knives, screw drivers, and otherobjects to clean the hardened carbon from the grooves. Even skilled mechanics have had great difficulty in preventing scoring or scratching of the grooves as the hardened carbon has been chipped away.
Attempts have been made to place commercial products on the market which provide for the cleaning of a single groove at a time on a piston. However, experiences prove that such devices are as time consuming as traditional methods of chipping byhand, and moreover do not clean all of the foreign material and accumulated carbon from the grooves, so that a manual second cleaning has been required. There is nothing known in the act or in the marketplace which will permit a mechanic to efficientlyclean all of the grooves on a piston quickly and efficiently.
It is an objective of this invention to provide an apparatus for the efficient and fast cleaning of all ring grooves in a piston at one time. It is a further objective to provide means for bearing the pressure exerted by cleaning blades withinthe grooves of the pistons.
SUMMARY OF THE INVENTION
The apparatus of the invention is adapted to clean simultaneously all ring grooves in a piston. The apparatus has a generally cylindrical shaped housing, which can be constructed in two halves with appropriate means for securing the halvestogether around a conventional piston. The housing can also be of unitary construction with provision for insertion of the piston into the housing through one end thereof. The housing can be constructed of any material which will withstand thepressures placed upon it. For example, light weight steel and even some hardened plastics could be used in construction of the housing.
A plurality of cleaning blades are disposed within the housing and are arranged in mutually spaced apart relationship along the axial length of the housing interior. The blades extend circumferentially around the interior circumference of thehousing and are spaced so that each blade can be inserted into a ring groove of a piston when the piston is in place within the housing. The cleaning blade can be of unitary construction, or can comprise an elongate member attached at one end to thehousing and having a sharp tooth patched to the other end of the elongate member. The tooth can be adapted to fill the ring groove so that the entire cross sectional area of the groove is cleaned out by the tooth as the piston is rotated with respect tothe cleaning blades and the housing. The cleaning blades can be adjustable with respect to the spacing between the blades, so that the apparatus can accommodate pistons having grooves in various locations upon their surfaces. Preferably, the cleaningblades are removable from the housing, in the event of breakage or dulling of the blade or tooth.
The apparatus has biasing means for exerting pressure upon the cleaning blade to hold the blade within the ring groove with sufficient pressure to remove the accumulated carbon and other foreign material from the groove. Preferably, the biasingmeans is adjustable so that appropriate pressure can be exerted upon the cleaning blade to match the force exerted by the blade to the hardness of the carbon and other foreign matter found within the groove. By adjusting the biasing force, care can alsobe taken to prevent scoring of the surface of the groove by the cleaning blade.
An additional feature of the invention includes means for insuring that the piston when in place within the housing is not displaced radially with respect to the housing as the piston is rotated. Such radial displacement would possibly result inscoring or scratching of the groove surface by the cleaning blade. It would also reduce the efficiency of the cleaning process by permitting the blade to pass over hardened carbon material rather than cleaning it from the groove. Preferably, such meanswould comprise a series of rollers disposed along the interior surface of the cylindrical housing. The rollers would fit snugly against the external surface of the piston and hold it snugly in place within the housing, while permitting the piston torotate therein. Under certain circumstances, the housing itself could be constructed to such close tolerances, that a particular sized piston would fit snugly within the housing in the absence of such roller means. The apparatus also preferably hashandle means for ease in rotating the apparatus around the piston.
The best mode presently contemplated for carrying out the invention is illustrated in the accompanying drawing, in which:
FIG. 1 is a top plan view of the apparatus showing a piston in place in the apparatus; and
FIG. 2 a side elevational section taken along broken line 2--2 of FIG. 1 showing placement of the cleaning blades with respect to the piston ring grooves.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
As shown in FIGS. 1 and 2, a preferred embodiment of the invention has a housing 10 which is generally cylindrical in shape. Housing 10 is formed of two halves which are aligned with appropriate hinge means 11 on one side thereof, so that thetwo halves can be opened and a piston 12 inserted into the housing 10. The other side of the two halves of housing 10 can be secured together by bolt means 13, which in this embodiment is moveably secured 14 to one half of housing 10, while the otherhalf is secured to the bolt means by flange 15 and nut 16.
A plurality of roller means 17, in this embodiment three are rotatably secured to the interior of housing 10, so that they fit snugly around piston 12 and prevent radial displacement of the piston as it is rotated with respect to housing 10. While more or less than three rollers 17 can be used, this number appears to be optimum.
A plurality of cleaning teeth 18, in this embodiment three, are disposed in mutually spaced-apart relationship along the axial length of the interior of the housing 10 in register with the ring grooves 19 in piston 12. Cleaning teeth 18 arereplaceably secured to one end of elongate member 20, which is moveably attached at its other end to housing 10 by means of a bolt 21. This enables the blade means comprising member 20 and teeth 18 to be replaced easily in the event of breakage. Teeth18 are disposed at such an angle with respect to groove 19 that maximum pressure can be exerted upon the groove by biasing means in this embodiment leaf spring 22, to force hardened carbon and other foreign material from the groove 19 without scoring oror otherwise damaging the grooves.
Leaf spring 22 applies pressure to elongate member 20, which may also be fabricated of spring steel or the like. In this embodiment, leaf spring 22 is made adjustable as to the amount of force exerted upon member 20 by a spring-loaded screw 23,which extends for convenience to the exterior of housing 10.
Also for convenience, one or more handles 24 can be attached to housing 10 to aid in rotating the housing with respect to piston 12 when in place.
Whereas the invention is illustrated and described herein with respect to certain preferred embodiments, it is to be understood that many variations are contemplated without departing from the inventive concepts which are particularly pointed outin the appended claims.